Tunnel construction



H. W. SCHLUETER. TUNNEL co'NsTRucTIoN.

l l APPLICATION FILED MAY I2 19111 1,353,274. PatentedSept. 21, 1920. 2 SHEETS-SHEET l.

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TUNNEL CONSTRUCTION.

APPLICATION FILED MAY I2. |911.

1,353,274. Pmnwasept. 21,1920.

2 SHEETS-#SHEET 2.

in many building,

i UNITEn. STATES PATENT OFFICE.

HENRY W. SCI-ILETER, OF LOS ANGELES, CALIFORNIA.

TUNNEL' CONSTRUCTION.

Specication of Letters Iatent. Patented Spt. 21, .19207.

Application met May 12, 1917. serial No'. 168,231.

to drive a bore through the earth and to line the roof of this bore with a metal, stone, brick, or concrete lining. This lining must cases have great mechanical strength, andv at the same time it must be cheap to construct. In the art of tunnel concrete linings are common, but the construction of such linings is often a difficult matter, as elaborate forms must be erected and there is considerable difficulty in handling large masses of wet concrete in the small space available in such'construction.

The method employed by me, and the advantages thereof, will be set forth in the following specification. Y Y In the drawings, which are for illustrative Vpurposes only:

Figure 1 is a longitudinal section through a tunnel in which'my invention is used.

Fig. 2 is a section on a plane `represented by the line 2-2 of Fig. 1.

Fig. 3 is a section on a plane represented bytheline 3- 3 of Fig. 1.

' Fig. 4 is aA view, on an enlarged scale, of a pair of precast members used in myinvention, with a single rib cast therebetween, the rib being shown in section Y Fig. 5 is a similar view showing `a preferred form of retaining means.

Fig. 6 is a perspective view of av portion of the tunnel lining, a number of the precast members being broken away to better illusy.trate vthe form and location of the ribs.

best be described by describing the method of drivin a tunnel and lining it by my method. ne very convenient method is illustrated in the draw- My invention can ing resting on ings, but it is evident that other'methods may be used without departing from the Y spirit of my invention, as set forthiin the claims. InV the method illustrated, a pair of footing tunnels 11 are first driven at either side of the tunnel and at .the base thereof.

Footings 12`are constructed in these footing i tunnels preferably of concrete which may be reinforced'.4 A main bore 13 of more or'less annular shape is then driven, leaving a central core 111. A false ring 15 ofy wood or metal is then supported on suitable jacks 16 on projecting ledges 17 of the vfootings 12, this ring having the same generalshape as the desired inside wall of the tunnel.`

A built-up lining is then formed on the ring 15, this lining being constructed of precast reinforced concrete members 21. .These members when laid up, as shown in the drawing, form an annular ring having the same inside shape and sizel as the inner wall of the desired tunnel as defined by the false ring 15. Each of the members 21 is formed -of fiat sides 22 which projected form adihedral angle having its apex at the center of the tunnel. and'having edges 23 which are parallel planes. The inner surfaces 24, and

the outer Surfaces 25 are preferably portions of cylinders'having'theircenter at the aXis of the tunnel.

vsurfaces 24 form the inner surface of the linthe false ring 15. The Vmein- These members 21 are laid g one upon the other on'the sides 22 with the bers 21'are preferably laid up inmortar or neat cement, and when assembled form a continuous lining for the main bore 13. `If desired, the members 21 .may bereinforced in any suitable manner as by rods 26.

Formed in each of the membersv21 at either edge thereof are recesses 31. The

members 21 are extended to form lips 321at either side of the recesses 31, as shownin Fig. L For the purpose of tying the different courses of members 21together during construction, I provide metal clenching bars 33 which are hooked over the lips 32 as the courses are laid.V f

'At the same time, or before the main'bore 13 is driven, filling tunnel 1S is driven at the extreme top of and outside the main Vbore V13. As the courses of members 21 are laid up they Vform arches temporarily supported by the false ring 15. The spaces 31 in adjacent members 21 form continuous channels 41 which extend completely around the walls of the tunnel from one footing to the other. As soon as-a course vor member 21 is laid, and before the .last or keystone member 21 is inserted in the arch, the space 41 is filled with concrete forming a continuous rib 52. If desired, an opening may be left in the outer surface of the keystone member 21 through 'which the cement may be inserted in the channels 41. Reinforcement 53 may be placed in the channels 41, as they are produced, so that the ribs 52 are reinforced. The channels 41 are most conveniently filled throughA theuse of the filling tunnel 18, concrete being carried by any convenient means up the inclined face of the core 14 and into the forward end of the filling tunnel 18. A number of courses of members 21 are preferably laid at one time on the false ring 15; As soon as these courses are completed and the ribs 52 are poured, the false ring 15 is lowered by means of the jacks 16, andthe ring l5 is moved forward and jacked up into its new position where newy courses may be built on l it. The core 14 is excavated at the convenience of theworkers as the lining progresses. In the `place of using the retaining mem,- bers 33, shown in' Fig. 4, I find in many forms of construction that longitudinal reinforcements, as shown in Fig. 5, are preferable. In this form, openings 60 are formed through the centers of the members 21, and rods 61 are used to tie the members n 21 together longitudinally. As the members 21 are put in place, several courses at a time, it is convenient to Vuse rods 61 which pass through several members 21, these rods being threaded at either end into couplings 62 which are made of some length and which abut on washers 63. As new courses are added, new rods 64 are screwed into the couplings 62, so'that therods 61 and 64 and the couplings62 form a continuous dinal metal reinforcement which y passes through all the members 21 on either side of -the tunnel at any level and which is locked solid in place b the ribs 52.

Where it is esired to line old tunnels, no preliminary boring is necessary, the false ring 15v being erected inside the tunnel and the work progressing thereon as has just been explained.v It is to be noted that this workcan be done without blocking the tunnel, so that it can, with proper precautions,

Abe used for traiic during the construction period.

It will be noted that by using my method ished construction.

longitunels 41. This may be done by pumps in some cases. The construction of the tunnel lining therefore progresses rapidly.

While this low cost is an important factor in the success of my method, it is not as important as the very uniform character, and, therefore, great reliability of the iin- The members 21 are precast outside the tunnel under absolutely controlled conditions. They are of the proper mixture and they are castA and set under ideal conditions. The result is that the members 21 are all alike and, of the most reliable' character. The lining formed of such members is therefore much superior to ,i

any masonry lining, and this linin alone is of great strength and rigidity. A er the lining formed of the members 21 is'completed, the ribs 52 are cast therein.' It will be noted that the members 21 taken together make a perfect form for the ribs 52.v vThechannels 41 are entirely closedexcept at the .Y

top where the channel 41 is filled, andall stone, earth, etc., is therefore excluded therefrom. As a result, the ribs 52 are of clean and uniform concrete. This concrete is inside an imperviouswall o f precast concrete formed by the members 21 and it sets under ideal conditions.

The completed construction comprises a biiilt-up precast lining in which the cast ribs 52 are embedded. The ribs 52 servenot only to support lthe roof of the tunnel resting on the footings 12, but they also tie tofrether' the adjacent courses 'of members 21. As the members 21 may be readily" tested and inspected outside thel tunnel, the character of the `completed work is assured, as the pouring or casting ofthe ribs 52Y is a matter on which even unskilled labor cannot go wrong. fV i I believe that I am the first toemploy ribs 52 which arevc'astpin place in a built-up llining formed of precast slabsl ormembers 21.

I claim as my invention 2f 1. A tunnel lining.comprising-.alternate courses of preformed members and cast monolithic ribs, each of said courses, being continuous and self'supporting .throughout4 .Y the arch; said cast monolithic ribs being ii 1-V terlocked with the 'adjacent fcour'se's in such a manner as to tie said courses together; a series of rods placed parallel with the axis of theV tunnel and passing through said V.preformed and cast members; and fastening 'i Lessen a means on each rod for securing either end gf said rod to one of said preformed memers.

2. A tunnel lining as in claim l in which 5 said fastening means comprises a nut threaded on said rod.

3. A tunnel lining as in claim 2 in which said nuts are each sufficiently long to receive f the ends of two adjacent rodsJ thus oonnect ing a line of said rods to form a continuous 10 tie member.

In testimony Wheieotl I have hereunto set my hand at Los Angeles, California, this 3rd day of May, 1917.

HENRY W. SCHLUETER. 

